<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>购物车</title>
    <style>
           
        table {
          border: 1px solid #e9e9e9;
          border-collapse: collapse;
          border-spacing: 0;
          align-items: center  ;
          width: 800px;
          
        }
        table {
            margin-left: 300px;
            margin-top: 100px;
            
        }
         h2 {
            margin-left: 300px;
         }
        th,
        td {
          padding: 8px 16px;
          border: 1px solid #e9e9e9;
          text-align: left;
        }
    
        th {
          background-color: #f7f7f7;
          color: #5c6b77;
          font-weight: 600;
        }

      </style>
      <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
    <div id="app">
        <div v-if="books.length">
        <table>
            <thead>
            <tr>
                <th></th>
                <th>书籍名称</th>
                <th>出版日期</th>
                <th>价格</th>
                <th>购买数量</th>
                <th>操作</th>
            </tr>
            </thead>
            <tbody>
            <tr v-for="(item, index) in books">
                <td>{{ item.id }}</td>
                <td>{{ item.name }}</td>
                <td>{{ item.date }}</td>
                <td>{{ item.price}}</td>
                <td>
                <button @click="decrement(index)" :disabled="item.count <= 1">-</button>
                {{ item.count }}
                <button @click="increment(index)">+</button>
                </td>
                <td>
                <button @click="deleteBook(index)">移除</button>
                </td>
            </tr>
            </tbody>
        </table>
        <h2>总价格：{{ fullprice  }} ￥</h2>
        </div>
        <h2 v-else>购物车为空</h2>
    </div>

    <script>
        const vm = new Vue({
        el: '#app',
        data: {
            books: [
            { id: 1, name: '《java编程思想》', date: '2020-9', price: 98.00, count: 1 },
            { id: 2, name: '《数据分析与数据原理》', date: '2019-2', price: 39.00, count: 1 },
            { id: 3, name: '《Hadoop权威指南》', date: '2019-10', price: 59.00, count: 1 },
            { id: 4, name: '《代码大全》', date: '2018-8', price: 128.00, count: 1 },
            ]
        },
        computed: {
            fullprice() {
            var fullprice = 0;
            for (var i = 0; i < this.books.length; i++) {
                fullprice += this.books[i].price * this.books[i].count
            };
            return fullprice;
            }
        },
        methods: {
            increment(index) {
            this.books[index].count++
            },
            decrement(index) {
            this.books[index].count--
            },
            deleteBook(index) {
            //从当前索引开始, 删除1个
            this.books.splice(index, 1)
            }
        }
        })
    </script>
</body>
</html>